Driving key



UNHE

STATES ROBERT A. SMITH, OF MAHWAH', NEW JERSEY, AND EDWARD B. GRAY, OF TROY, PENNSYLVANIA, ASSIGNORS TO SMITH & SERRELL, A COIARTNERSHIP COMPOSED OF ROBERTA. SMITH, MAHWAH, NEW JERSEY, AND JOHN J. SERRELL, OF

ELIZABETH, NEW JERSEY.

DRIVING KEY.

Application filed October 24, 1922. Serial No. 596,559.

drawing, which forms part of the same.

This invention relates especially to selffitting driving keys provided with cutting edges or portions on one or more of the driving faces of the key so that it may cut or finish its own keyway when driven into the usual rough keyways in the shaft and other cooperating part as is described and claimed in the application of Robert A. Smith, Serial No. 57 3,195, filed July 6, 1922. It is often advantageous'to withdraw these selffitting keys and for this purpose it is desirable to form a threaded withdrawing end on the driving end of the key which is remote from its cutting edges and by hardening and, if desired, tempering this threaded portion it may be used repeatedly in forcibly withdrawingthekey from its fitted keyway as by crewing one ormore nuts over this threadzd withdrawing end or by screwing a nut thereon and prying or wedging under the nut with any suitable device. It is also of advantage in many cases to form the key witha reducedand preferably rounded driving end beyond.thi's threaded end or portion so that the key may be driven into its keyway' with a hammer, for instance, withoutinjuring the. adjacent withdrawing thread-on the key;

In the accompanying drawingshowing in a somewhat diagrammatic way several illustrative embodiments of this invention:

Fig. 1 is a sectional view showing the use of such a keyl'f Fig. 2 is a similar view 'shdwing another 45. method of withdrawal.

Fig. 3 is a top view on a larger scale showing such a key and'a cooperating double threaded withdrawing nut.v

Fig.4 is an end view of this key, and

Fig. 5 is a side view of another illustrative ke is indicated in Fig. 1, the self-fittin' key 1 which may have any desired form 0 cutting edges such as 3 on one or more of its drlvmg faces and-on the other faces of the key, if desired, and which may have a reduced width guiding aligning portion or face 2 ahead of each of these cutting edges, may be formed on its rear or driving end with a threaded withdrawing end 6 which is preferably an integral threaded portion of the special steel key and heat treated or hardened and tempered to secure the desired qualities in the steel. After such a key has been driven into the rough keyway 11 in the shaft 12 and the cooperating rough keyway in the gear or other cooperating member 15 on the shaft, it is often desirable and necessary to promptly. withdraw the key in order to remove the gear from the shaft, for instance. Under these conditions it is advantageous to screw a double threaded w1thdrawing nut such as 18 on the projecting threaded withdrawing end 6 of the key which is preferably substantially tangent to the key body as is shown in Figs. 1 and .3 so that the threaded hole 16 in this nut is screwed on to the key end as far as the threads 6 thereonextend. In this waya projecting externally threaded withdrawing member is provided securely attached to the key and one or more standard hexagonal nuts such as 19, 2O ma be screwed on to this outer threaded portion 17 of the externally and internally threadedwithdrawing nut as is indicated in Fig. 1. When these nuts 19, 20 are screwed on by a suitable wrench, for instance, the withdrawing nut 18 forcibly withdraws the key-l-from the keyway 11 and a key three or four in ches long can be withdrawn in this way in a few minutes without any substantial danger of breaking or injuring the key orthe parts.

which it connects. Another way inwhich this threaded with drawing end 6 may be used is illustrated in Fig. 2 in which a regular hexagonal or otherv nut 22. isshown -as screwed on the threaded withdrawing end 6 of the key 1. Then the end 23 of the pinch bar or lever 24 is inserted under the no. "and sufiicient pressure applied thereto to" withdraw the nut and connected key a quarter or a half an inch at a time, suitable blocks orspac: ing members being of course applied beneath the pinch bar as it works the f increment by increment.

Y may of course be unscrewed from the key same.

after it is withdrawn and the key driven home into its keyway again in which connection a reduced diameter driving end or projecting portion 7 ispreferably formed on this driving end of the key which is advantageously formed with rounded edges 8 so that the key can be repeatedly driven even with an ordinary hammer without any substantial injury to the withdrawing thread 6. The cutting heads or ends of these keys may be given any desired form and, as indicated in somewhat greater detail in Fig. 3, the two driving faces of the key may be provided with cutting edges 3 which may have a cutting face or angle 4 of seventyfive degrees or so, the adjacent chip recesses 5 bein of such size as to accommodate the usual t in chips which are cut from the keyway in resizing it as the key is driven home. Guiding aligning faces or portions 2 are preferabl formed ahead of each of these cutting e ges and are preferably of slightly less width than the drivin faces of the key body so as to act effective y in keeping the key properly in line with the rough keyway as it is driven home. If desired, cutting edges such as 9 may be formed on one or both of the other sides or faces of the key 1 and one convenient and desirable arrangement is shown in Figs. 3 and 4 as comprisin a curved chip discharging recess 10 which may be milled or ground in the front end of the key as indicated in Fig. 4 so that narrow or practically sharp edges are thus formed adjacent each-of the guiding faces 2 so that these edges act effectively as guiding members in connection with the cutting edge 9 which may be substantially square so as to have about a ninety degree cutting anglewhich tends to force the key downward away from this edge as it is driven into the keyway. As shown in Fig. 5, the key 31 may have a similar threaded withdrawing end 6 and reduced driving endor portion 7, the front or cutting end of the key being shown as provided with several cutting edges 33, 34 which may be conveniently', formed on the key when the chip recess 35 is milled or ground out of the The somewhat narrower guiding aligning faces 32 may be formed, if desired, ahead ofeach of these cutting edges In making these heat treated hardened steel keys it is desirable to grind at least their driving faces to size after they have been hardened and tempered and for this reason it is' quite desirable to have the threaded withdrawing end of the key of somewhat less diameter than the thickness of the key body, although if desired, the threaded withdrawing end may be substantially tangent to the key body without interfering with such grinding or other finishing operation.

Such a nut 22 3 nection with a number of illustrative embodiments, forms, proportions, parts, shapes, materials, arrangements, methods of manufacture and use, to the details of which disclosure the invention is not of course to be limited, since what is claimed as new and what is desired to be secured by Letters Patent is set forth in the appended claims.

We claim:

1. In self-fitting driving keys, a hardened rectangular sectioned key having a cutting head comprising cutting edges adapted to resize the keyway as the key is forced into the same and having on-its opposite driving end a threaded withdrawing end, and a cooperating internally and externally threaded Withdrawing nut adapted to be screwed on said threaded withdrawing end of the key to enable said key and nut to be withdrawn by screwing a nut on the external threads ofsaid withdrawing nut.

2. In self-fitting driving keys, a rectangular sectioned key having a cutting head adapted to resize the keyway as the key is forced into the same and having on its opposite end a threaded withdrawing end, and

a cooperating internally and externally threaded withdrawing nut adapted to be screwed on said',threaded withdrawing end of the key to enable said key and nut to be withdrawn by screwing a nut on the external threads of said withdrawing nut.

3.. In self-fitting driving keys, a rectangular sectioned key having a cutting head comprising cutting edges adapted to resize the keyway as the key is forced into the same and having on its normally projectin end a hardened threaded withdrawing e and a double threaded withdrawing not adapted to be screwed on said threaded withdrawing end of the key to facilitate the withdrawal of said key.

i 4. In driving keys, a rectangular sectioned key having on its normally projecting end a hardened threaded Withdrawing end of not substantially greater diameter than the thickness of the key body, and a nut adapted to be screwed on said threaded withdrawing end of the key to facilitate the withdrawal of said key.

5. In self-fitting. driving keys, a hardened rectangular sectioned key having a cuttin head and having its opposite end provided with an integral threaded withdrawing end of not substantially greater diameter than the thickness of the key body and formed with a reduced diameter driving end projecting therefrom to enable a nut to be screwed on said threaded withdrawing end and facilitate the withdrawal of the key after it has been forced into a keyway.

6. In self-fitting driving keys, a rectanguhaving its opposite end provided with a hardened steel threaded withdrawing end of not substantially greater diameter than.

the thickness of the key body to enable a nut to be screwed on said threaded withdrawing end'and facilitate'the withdrawal of the key after it has been forced'into a keyway.

7. In self-fitting driving keys, a hardened polygonal sectioned key of heat treated steel having its normally projecting driving end provided with an integral threaded withdrawing end substantially tangent to the key body to enable a nut to be screwed on said threaded withdrawing end and facilitate the withdrawal of the key after it has been forced into a keyway.

8. In driving keys, a hardened polygonal sectioned key of heat treated steel having its normally projecting end provided with an integral threaded Withdrawing end of somewhat less diameter than the thickness of the key body to enable a nut to be screwed on said threaded Withdrawing endand facili tate the withdrawal of the key after it has been forced intoa keyway.

ROBERT A. SMITH. EDWARD B. GRAY. 

